This invention relates to athletic sunglasses with a head mounted elastomerically powered tensioning system used to rotate a lens from the viewing position in front of the eyes, to a non-viewing position above the forehead.
Outdoor athletes today are more cognizant than ever of the need to wear sunglasses as a protective barrier from the elements. Sunglasses shield the eyes from accidental invasion of foreign objects, and provide protection from the sun""s ultraviolet A, 315 to 400 nanometers, and ultraviolet B, 280 to 315 nanometers, radiation levels.
Although sunglasses have been around for a long time, the basic design remains the same. Two earpieces that attach to a lens frame, that attaches to a nosepiece. Unfortunately, the shape and construction of the human head does not lend itself well to attaching ordinary sunglasses to its protrusions.
Typical sunglasses have earpieces that fit around the ears, and provide a pulling force to keep the nosepiece from sliding down the nose. The nosepiece resists this pulling force by digging into the bridge of the nose. The head feels this opposition of forces whenever sunglasses are worn. The result of these two opposite forces is sore ears and a sore nose. This is one of the problems that is solved by this invention.
The other problem of ordinary sunglasses is the inability to conveniently remove and stow the sunglasses from the viewing position when conditions require. One such condition is the wiping of perspiration from around the eyes during the heat of athletic competition, or simply the need to temporarily remove the sunglasses from the viewing position. Ordinary sunglasses require a place to be stowed during these conditions, and this is another problem solved by this invention. The outdoor athlete needs a sunglasses system that will a.) provide a tensioning system that will keep the sunglasses comfortably in place even during rigorous physical activity, b.) have the ability to quickly and easily rotate the sunglasses out of the line of sight to wipe perspiration from around the area of the eyes and then quickly and easily rotate back into the line of sight, even during the physical activity, and c.) provide easy adjustability for properly locating the sunglass lens and frame to the face.
With regard to using tensioning systems to hold the sunglasses in place, the prior design of U.S. Pat. No. 4,885,808 to Carpenter, issued Dec. 12, 1989, is indicative of the simple flip up approach of using a coiled spring tension device to hold the sunglasses in place. This arrangement also allows the sunglasses to be rotated into and out of the line of sight of the wearer. However, this design is fragile because of the single tiny flip up mechanism used to attach the eyepiece to the headband. This one fragile attachment point would allow even the smallest of impacts experienced during a sports activity to drive the eye pieces into the wearers eyes and face, posing an unacceptable risk of damage.
With regard to the ability to quickly and easily rotate the sunglasses into and out of the line of sight of the wearer, reference is made to U.S. Pat. No. 4,616,367 to Jean, issued October 1986, U.S. Pat. No. 4,712,254 to Daigle, issued December 1987, and U.S. Pat. No. 4,811,430 to Janusz, issued March 1989, as being indicative of the approaches used to hide the eyepieces in a headband to remove them from the line of sight of the wearer. This approach is not only cumbersome and time consuming for the hands to operate, but more importantly, it drastically limits the size and shape of the eyepieces that can be used because of the need to fit inside the headband when not in use. Since these eyepieces are too small and too flat to adequately follow the contours of the head and face, unfiltered sunlight as well as foreign objects are allowed to reach the eyes from the sides and bottoms of the eyepieces.
A later design to solve the problem of protecting the eyes from unfiltered sunlight and foreign objects was shown by U.S. Pat. No. 4,852,189 issued to Duggan in August 1989, by using a one-piece wrap around eyepiece held in place by a hook and loop attachment of the headband. Although the eyepiece gave better eye protection, it was still cumbersome and unwieldy to operate by requiring two hands to change the position of the eyepiece.
A more logical design to provide a rotating eyepiece was provided by U.S. Pat. No. 5,105,475, issued to Lynd on Apr. 21, 1992, by providing a wrap around eyepiece that rotates up and down by means of two arms attached to a cap headband. However, no tensioning system was provided to keep the eyepiece firmly in place in the two desired positions. And finally, the eyepiece had to rotate into a cap bill, thus limiting its travel, making the design unsuitable for a vigorous sport like basketball. Another visor related design was made with U.S. Pat. No. 5,239,703, issued to Nordin et al in August 1993. This positional visor arrangement has two obvious drawbacks. The first is the pivot end of the journalling pin not being secured, which allows the journalling pin to slip out of the journalling opening when the visor is in either the up or down position. The second drawback is the obvious sliding friction required to expand the journalling opening for the journalling pin to rotate. Large bending moments are generated almost instantaneously during the first small movement of the journalling pin since the maximum rigidity of the journalling opening is located in the radiused corners. There is no smooth gradual increase of the forces created during operation.
A cap visor related design was made with U.S. Pat. No. 4,541,125, issued to Phillips in September 1985. However, there is no tensioning system to raise and lower the eyeshield, plus a fragile single attachment and rotation point for the eyeglasses makes this design unsuitable for aggressive sports. Even a mild impact in the area of the rotation attachment point could send the eyeglasses into the eyes and face of the wearer.
A similar design of U.S. Pat. No. 4,901,374, issued to Van der Woude in February 1990 is also based upon the single fragile attach and rotate point and same lack of a tensioning system to raise and lower the eyeshield.
A welder""s eyeshield was invented with U.S. Pat. No. 2,588,553, issued to McWethy in May 1948, and U.S. Pat. No. 2,700,158, issued to Larsen in January 1955, that rotated a protective shield into and out of the wearers line of sight. The design however, has no tensioning device to raise and lower the eyeshield, but instead uses the wearer""s chin to perform this function. This design is not only cumbersome, but also limited in its applications in sports.
A similar invention, U.S. Pat. No. 2,245,990, issued to Loud in June 1941 was used to rotate a protective eyeshield by means of a single hinge point and springs to assist raising the eyeshield. The use of the long coiled springs provides tension in only one direction. Tension is provided to assist the upward rotation of the eyeshield, but provides no assistance in the lowering of the eyeshield, thus the design must use snap catches on each side to keep the eyeshield from springing upward during line of sight use.
U.S. Pat. No. 2,187,932, issued to Cornell in January 1940 was a more efficient use of the spring by having the spring not only provide force to raise the eyeshield, but also to provide force to lower and hold the eyeshield in the viewing position. The drawback of using a spring-operated system is the bulky nature of their design. Springs do provide tension, but at the expense of precious available space around the forehead. To provide a sleek, compact design for the fashionable sports sunglasses market, the required tension must be supplied by a smaller and more efficient method than longitudinal coiled springs.
A similar approach, but a more complex design, was used in U.S. Pat. No. 2,103,006, issued to Helfenstein et al in Dec. 21, 1937. The springs were used to balance the welding hood in a desired viewing position, rather than provide force to snap the protective lens into and out of the viewing position. This design also required the considerable bulk and space inherent in the use longitudinal coiled springs.
U.S. Pat. No. 5,752,280, issued to Joe D. Hill in May 1998 incorporated improvements to this design concept. However, this design also has deficiencies that have prevented the design concept from reaching its maximum efficiency in the operation of the tensioning system, and the efficiency of the adjustability features.
Specifically, the ring described in the referenced patent must travel a circuitous rout around two arms and bend around as many as four direction changing guides to perform its function. The efficiency loss of the O-ring in this configuration, measured as ounces of force at the attach point of the arm to the lens, that is, force available to lift the lens, has caused the retract mechanism to exert only 45% to 50% of the force available by the simpler more efficient proposed invention.
Also, the O-ring design itself is deficient in maximizing the force available to lift and lower the lens. This simple O-ring design does not incorporate the advantages of multiple segments located inside the middle area of the O-ring. By having a single continuous body, space is wasted in the interior area of the O-ring that could be used to provide more force for the same occupied area by adding additional reinforcing material. Also, without interior reinforcements, the O-ring experiences stretching on only one side of it""s circumference when in operation. When the stretching reaches the O-rings stretch limit on the O-rings stretched half with increased tension, and the opposite half shrinks with reduced tension, it suddenly and rapidly moves to relieve the unbalanced condition and returns to a more evenly distributed stress condition. This condition is then repeated as the O-ring continues to traverse around the pulleys. These sudden movements diminish the smoothness of the operation as the O-ring is stressed performing its function.
The referenced patent also includes a single arm version, which is more efficient than a two arm version, that is not only burdened by the same O-ring deficiencies described above, but also suffers from an additional design shortcoming. The O-ring in the described single arm version is forced to bend around a stationary post used as the pivot point of the arm that attaches to the lens. This bending of the O-ring around a stationary non-rotating post induces efficiency losses that can be measured at the end of the arm where it attaches to the lens. Measurements taken indicate a loss of 30% of the lift force when the O-ring has to bend around the described post, as compared to an O-ring that does not have to bend around such a post, with all other conditions being equal.
With regard to the adjustability features of the referenced patent, the text describes the use of sliding plates, pop rivets, bushings, guide posts, threaded shafts, adjustment wheels, just to list a few of the parts, to move the lens forward and backward for the adjustability feature. This design is both complex and costly for a simple task of adjusting the lens to the face of the wearer.
Another solution is described in U.S. Pat. No. 5,752,280, entitled xe2x80x9cEye Protection Device for Headgearxe2x80x9d, issued to Joseph Hill on May 19, 1998. While this patent cures many of the problems already listed and discussed, it suffers from some limitations.
With the recent upsurge of interest in sports, a real need has developed for athletic sunglasses that realistically provide the comfort, protection, and style demanded by the modern athletes.
Previous patents have shown the need for a more compact design that can not only more efficiently rotate a protective lens into and out of the lie of vision, but also provide simpler more efficient adjustability for comfortably fitting the lens to the wearer""s face. A design that is able to accomplish both these tasks unobtrusively in the limited physical confines of today""s small, lightweight, fashion driven sunglasses designs.
Accordingly, besides the objects and advantages of my elastomerically operated adjustable sunglasses described above, several objects and advantages of the present invention are: to provide a soft, lightweight, comfortable, open cell moisture absorbent synthetic polymer foam material to help support the tensioning system on the head of the wearer; to provide a lightweight one piece contoured tinted optical quality eyeshield that is curved to closely emulate the shape of the face, thereby protecting the eyes from unfiltered sunlight as well as the introduction of foreign objects;
to provide a tensioning system to rotate the eyeshield into and out of the viewing position that is simple, efficient, lightweight, and economical compared to springs, cams, latches and other bulky mechanical systems used in previous patents;
to provide a head mounted elastomerically operated tensioning system that applies force to keep the eyeshield securely in place in the normal viewing position; then decreases the force to zero as the eyeshield is manually lifted to the equilibrium position toward the forehead, then applies force in the opposite direction to snap the eyeshield up to the out of viewing position without further manual assistance;
to provide the same head mounted elastomerically operated tensioning system that applies force to keep the eyeshield securely in place in the out of viewing position above the forehead, then decreases the force to zero as the eyeshield is manually pushed down to the equilibrium position toward the forehead, then applies force in the opposite direction to snap the eyeshield down to the normal viewing position with out further manual assistance;
to provide an elastomeric H shaped tensor for operating a tensioning system that provides more force per square inch of area due to the addition of an H shaped reinforcement area to the interior area, unlike previously used standard O-rings with vacant interior areas;
to provide an elastomerically operated tensioning system that operates without bending the elastomeric H shaped tensor around obstructions in its path during its operation, as compared to previous patents, thus increasing efficiency;
to provide an elastomerically operated tensioning system that rotates the protective eyeshield with a smooth, fluid, continuously variable force that simulates the feel of a hydraulic movement; to provide a simple, compact adjustability system that not only adjusts the placement of the protective eyeshield in relation to the wearers nose and face, but also allows the protective eyeshield to be easily replaced with a different color or style of protective eyeshield, unlike previous patents using complex and costly screws, threaded shafts, adjustment wheels, sliding plates and other devices; to provide a nosepiece that can be snapped into and out of the protective eyeshield, providing additional adjustability of the protective eyeshield to the face of the wearer by having the capability of using different sizes and shapes of nosepieces;
to provide an elastomerically operated tensioning system on each side of the head and connected to the protective eyeshield by means of a single arm on each side of the protective eyeshield, thus approximately doubling the efficiency of operation as compared to previous patents using pairs of arms on each side of the head;
to provide an elastomerically operated tensioning system on each side of the head, connected to the protective eyeshield by means of a single arm on each side of the protective eyeshield and this single arm being connected to the eyeshield with a solid non pivoting connection, creating a simpler more efficient connection between eyeshield and tensioning system;
to provide a pivoting, adjustable elastic strap for the head mounted tensioning system that will pivot, or rotate, to automatically assume the proper fitting angle between the elastic strap and the back of the head;
to provide a head mounted system that allows the nose piece of the protective eyeshield to comfortably rest on the nose of the wearer without the stresses applied by elastic straps of conventionally designed eyewear frames pulling the nosepiece into the nose.
Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.